diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/gpu/effects/GrSingleTextureEffect.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/gpu/effects/GrSingleTextureEffect.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrSingleTextureEffect_DEFINED
+#define GrSingleTextureEffect_DEFINED
+
+#include "GrEffect.h"
+#include "SkMatrix.h"
+#include "GrCoordTransform.h"
+
+class GrTexture;
+
+/**
+ * A base class for effects that draw a single texture with a texture matrix. This effect has no
+ * backend implementations. One must be provided by the subclass.
+ */
+class GrSingleTextureEffect : public GrEffect {
+public:
+    virtual ~GrSingleTextureEffect();
+
+protected:
+    /** unfiltered, clamp mode */
+    GrSingleTextureEffect(GrTexture*, const SkMatrix&, GrCoordSet = kLocal_GrCoordSet);
+    /** clamp mode */
+    GrSingleTextureEffect(GrTexture*, const SkMatrix&, GrTextureParams::FilterMode filterMode,
+                          GrCoordSet = kLocal_GrCoordSet);
+    GrSingleTextureEffect(GrTexture*,
+                          const SkMatrix&,
+                          const GrTextureParams&,
+                          GrCoordSet = kLocal_GrCoordSet);
+
+    /**
+     * Helper for subclass onIsEqual() functions.
+     */
+    bool hasSameTextureParamsMatrixAndSourceCoords(const GrSingleTextureEffect& other) const {
+        // We don't have to check the accesses' swizzles because they are inferred from the texture.
+        return fTextureAccess == other.fTextureAccess &&
+               fCoordTransform.getMatrix().cheapEqualTo(other.fCoordTransform.getMatrix()) &&
+               fCoordTransform.sourceCoords() == other.fCoordTransform.sourceCoords();
+    }
+
+    /**
+     * Can be used as a helper to implement subclass getConstantColorComponents(). It assumes that
+     * the subclass output color will be a modulation of the input color with a value read from the
+     * texture.
+     */
+    void updateConstantColorComponentsForModulation(GrColor* color, uint32_t* validFlags) const {
+        if ((*validFlags & kA_GrColorComponentFlag) && 0xFF == GrColorUnpackA(*color) &&
+            GrPixelConfigIsOpaque(this->texture(0)->config())) {
+            *validFlags = kA_GrColorComponentFlag;
+        } else {
+            *validFlags = 0;
+        }
+    }
+
+private:
+    GrCoordTransform fCoordTransform;
+    GrTextureAccess  fTextureAccess;
+
+    typedef GrEffect INHERITED;
+};
+
+#endif